The past 35 years have witnessed a revolution in evolutionary genetics that, like the proverbial The Little Engine that Could going over the mountain pass, shows no signs of slowing, much less stopping. To a considerable extent, we owe much to one per­ son, Richard Lewontin, for getting this little train over the hump and conducting it while the masses have shoveled coal into the boiler. Indeed, few have had such a substantive and pervasive impact on evolutionary biology in general, and so this edited volume is a welcome and well-deserved tribute to the powerful and varied influence of Lewontin on the fast-growing, important discipline of evolutionary genetics.